Abstract : The International Seismic Monitoring System needs the following three refinements: (1) regional adjustments of travel time curves and amplitude distance relations; (2) surface wave detection; and (3) location of small events. We have investigated anomalous structures of Bolivia, Chile and Colombia-Venezuela and established models of seismic wave velocity as%a function of depth; we have modelled the transmission of Love and Rayleigh waves in Bolivia and northern Chile; our station LPAZ of the Global Telemetered Seismic Network, our group of high gain French stations and our files of seismograms since 1913 make La Paz a National Data Center in central South America, authorized by the Bolivian Government. This has been complemented by: (1) participating with several foreign teams of seismologists, installing their equipment in Bolivia; and (2i) revising the history of seismicity of Bolivia and identifying six seismogenic zones, corresponding to the structural complexity.